With the growing popularity of integrated circuits (ICs) in various electronic applications, such as central processing units (CPUs), application specific integrated circuit (ASICs), and the like, the speed and complexity of ICs have increased significantly. Currently, ICs are increasingly utilized for development of dense high performance integrated circuit based devices that may integrate all (or nearly all) of the components of a complex electronic system into a single chip. Such devices are popularly known as System-on-chip (SoC) devices.
Typically, a SoC device includes a reference clock such that all the system clocks are derived from the reference clock. Sometimes, the reference clock may become faulty or inoperative due to a variety of reasons, such as crystal ageing, wire bond issues on board, silicon ageing and the like, which may be detrimental to the functioning of the SOC device. For several applications including automotive application, it is fatal to have the SoC device non-functional due to malfunction, such as ‘out of range’ condition, of the reference clock since almost all the system clocks are derived from the reference clock. Accordingly, it is very important for a SoC device to include a circuit that is capable of detecting a reference clock malfunction condition, and take a corrective action in a timely and cost efficient manner.